Field of the Invention
This invention relates to a framed soap composition having advantages that it may hardly crack and also hardly become swollen, even when any means is taken for its formulation, e.g., activators other than soap are added, in order to attain a preferable feel on use, and also having a high productivity comparable to milled soap. 2.
Description of the Related Art
From differences in production processes, soap can be roughly grouped into two types. One of them is milled soap and the other is framed soap.
The milled soap is obtained by adding a perfume, a dye and so forth to a soap base material obtained by heating and drying neat soap, well mixing them by means of a mixer, putting the resultant mixture to a rolling machine and an extruder to extrude and mold the mixture into bars while kneading and compressing it, and stamping the bar-like molded products thus obtained. The milled soap obtained in this way have advantages that it may readily dissolve in water or the like and also has a high productivity. On the other hand, however, the milled soap has problems that it tends to crack and tends to become swollen. In particular, it greatly tends to become swollen when it has a high water content or when it contains other activators.
As for the framed soap, it is obtained by adding various additives to neat soap, directly pouring the resultant mixture into a frame, and cooling it in the frame to harden, followed by drying. The framed soap obtained in this way is constituted basically of from 50 to 70% by weight of fatty acid soap, from 10 to 20% by weight of polyols (glycerol, etc.) and the balance being water, and has features that it may hardly crack and may hardly become swollen. Also, since it can be produced basically by pouring the neat soap into a frame, it can be produced at a lower cost in view of the cost of production facilities than the cost of production facilities for the milled soap.
The framed soap, however, has disadvantages that it takes at least a day or two days until the soap hardens and dries, and takes as long as about a month in the case of transparent soap, bringing about a problem of a very low productivity. For this reason, under existing circumstances, the framed soap has commercially a very small share except for transparent soap, despite the advantages that it may hardly crack and may hardly become swollen. This is because, as stated above, while it can be produced at a lower cost than the milled soap in view of the cost of production facilities than the cost of production facilities for the milled soap, its final products result in a greatly higher cost of production than the milled soap.
What is called light-weight soap or floating soap, in which air bubbles are entrapped, is also known as a type of the framed soap, see Japanese Patent Application Laid-open No. 4-218599. This publication discloses a floating soap produced by melting a neat soap composed of from 10 to 50% of coconut oil and 50 to 90% of beef tallow and having a water content of from 28 to 35%, introducing the resultant molten material into a high-shear mixing machine, blowing and mixing high-pressure air to incorporate air bubbles into the molten material, pouring into a soap frame the resultant mixture incorporated with air bubbles, and leaving it to cool to harden.
However, the formulation of soap as disclosed in Japanese Patent Application Laid-open No. 4-218599 has caused a problem that the bubbles can not be well retained as they stand to cause phase separation into crushed bubble phase and solid phase to become hard.